1. Field
Example embodiments of the inventive concepts relate to backside illumination CMOS image sensors, and more particularly, to backside illumination CMOS sensors including photodiodes with convex light-receiving surfaces and methods of manufacturing the same.
2. Description of the Related Art
A CMOS image sensor may include a plurality of unit pixel elements (pixels) that convert a sensed image into an electric signal. Each unit pixel may include a photo-diode that senses an input image signal and a plurality of MOS transistors that may be used to convert the sensed image signal into an electric signal. Light may be received by the image sensor through a top surface of a chip including photo-diodes and MOS transistors formed thereon. Because a unit pixel includes not only the photodiode but also the MOS transistors, only a part of the unit pixel may be allocated to the light-receiving area of the photodiode.
A backside illumination CMOS image sensor may receive light through a bottom surface of a chip (e.g., a substrate). This backside illumination CMOS image sensor may be manufactured in such a manner that photodiodes and MOS transistors constituting the backside illumination CMOS image sensor are formed, the bottom face of the chip is ground to a thickness most suitable for receiving light, and a color filter and a micro-lens are formed on the ground bottom face.